Fluoride & Oxidative Stress: An Emerging Area of Concern

FAN Science Watch | Sept 29, 2004 | By Michael Connett

Evidence continues to come in demonstrating that fluoride may increase oxidative stress. This past week, Medline posted two new studies (1,2), which compliment 3 earlier studies this year (3-5) suggesting that this is in fact the case. Many more studies published over the past 15 years have reported similar findings (6-20), although some have not (21, 22).

As noted recently in a review by Dr. NJ Chinoy of India: “a comparatively smaller number of publications exist which do not subscribe to oxidative stress in fluorosis as opposed to the many that do… Strong evidence for oxidative stress by fluoride has been reported in a number of tissues (brain, liver, kidney, testis, cell lines, etc) of animals and humans” (22).

While more research needs to be done to resolve the various means by which fluoride can exacerbate oxidative stress, it is clear that this issue needs to be taken seriously. Oxidative stress is implicated in a wide range of human disease, from cancer, to diabetes, to brain disorders.

On the positive side, however, the link between fluoride & oxidative stress may help aid efforts to mitigate and reverse the symptoms among people suffering from fluoride toxicity. Some evidence is already available suggesting that this is the case. In 2002, Dr. AK Susheela, a consultant to UNICEF, and one of the world’s leading authorities on skeletal fluorosis, published a study (23) which showed that the use of anti-oxidants (in conjunction with substantial reductions in fluoride intake) could help bring about substantial improvement in humans chronically poisoned by fluoride. (An anti-oxidant, as suggested by the name, is a substance which can help counter and reduce oxidative stress.)

It’s been known for many years (24) that deficiencies of vitamin C (a powerful anti-oxidant) can be associated with more severe signs of fluoride toxicity in both animals and humans. As noted in a 1977 review on fluoride by the Canadian government:

“In a study of fluoride supplementation in monkeys, Reddy and Srikanti (1971) showed that a diet low in vitamin C enhanced the onset of skeletal fluorosis… Earlier, Gabovich and Maistruk (1963) had shown that vitamin C supplementation reduced the toxic effects of fluoride in industrial workers and in Guinea pigs. Marier and Rose (1971) discussed Russian studies in which fluorosis was found to be most severe in children who had a vitamin C deficiency. Marier and Rose also discussed Australian work, which showed that vitamin C supplementation alleviated fluorosis in Guinea pigs. It appears possible that chronic exposure to fluoride increases the metabolic requirement for vitamin C…” (24).

Finally, a quick reference to tea may be in order here. As many readers know, the tea plant is one of the rare plants that, even in the absence of acid rain (a factor which increases the accumulation of fluoride in many plants ), accumulates significant levels of fluoride present in soil. The resulting elevated fluoride content of brewed tea has been implicated as a contributing cause of endemic skeletal fluorosis in China and elsewhere (25).

However, teas are also known to have high levels of anti-oxidants as well. Thus, it may turn out that the high, yet varying, levels of anti-oxidants in teas may mitigate (at least partially) the effects of the fluoride. Of course, this isn’t the same as saying that fluoride in tea will have no effect, just that it might have less effect than would otherwise be the case. It should also be noted, meanwhile, that some commercial iced teas – which can have very high levels of fluoride (26) – may have depleted levels of anti-oxidants.